船舶制冷空调系统对环境的污染及其控制对策     

孙永明 《上海海事大学学报》1999,(4)

大气臭氧层的空洞已成为全球环境保护的焦点。中国的远洋运输船队是世界最大的船队之一。由于船用制冷空调系统在海运业的广泛使用,CFCs和HCFCs的使用使全球环境愈加恶化。从环保角度出发,本文介绍了国际上最新的CFCs和HCFCs的禁用日程及动向,比较了几种相对成熟的替代物,并从船舶制冷空调系统的操作和维护角度就如何避免环境污染提出了一些方法  相似文献   

从《第二十二条军规》看黑色幽默的艺术表现特征     

吴晓芸  熊万琼 《牡丹江教育学院学报》2008,(6)

约瑟夫·海勒的《第二十二条军规》是黑色幽默文学的典范之作,小说打破了传统的艺术表现形式,运用变形、夸张和滑稽讽喻的手法以及碎片化、集锦化的叙事结构揭示荒谬的时代和丑恶的社会本质,充分体现了黑色幽默的艺术表现特征。  相似文献   

Incentives and effort in the public sector: Have US education reforms increased teachers’ work hours?     

Christiana Stoddard  Peter Kuhn 《Economics of Education Review》2008

Beyond some contracted minimum, salaried workers’ hours are largely chosen at the worker's discretion and should respond to the strength of contract incentives. Accordingly, we consider the response of teacher hours to accountability and school choice laws introduced in US public schools over the past two decades. Total weekly hours of full-time teachers have risen steadily since 1983 by about an hour, and after-school instructional hours have increased 34 percent since 1987. Average hours and the rate of increase also vary widely across states. However, after accounting for a common time trend in hours, we find no association between the introduction of accountability legislation and the change in teacher hours. Education reforms are, however, associated with an increase in student test scores, presumably due to other types of changes in school and teacher behavior.  相似文献   

Three measures of returns to education: An illustration for the case of Spain     

María Arrazola  José de Hevia 《Economics of Education Review》2008

In this article, in a context of wage equations with sample selection, we propose a novel interpretation of the partial effects linked to education as additional measures of returns to education that complement the traditional one, which is directly obtained from the estimation of the wage offer equation. Using European Household Panel data for Spain these partial effects were calculated. The results show that there are incentives in Spain for investing in education not only because it means an increase in wages but also because it raises the probability of obtaining any wage at all.  相似文献   

Contractual governance and the choice of dispute-resolution mechanisms: Evidence on technology licensing     

Valérie Duplat  Régis Coeurderoy  John Hagedoorn 《Research Policy》2018,47(6):1096-1110

In fast-paced and knowledge-intensive environments, licensing partnerships can be powerful levers for market expansion. Research on the management of technology-oriented licenses has nonetheless pointed out the risks of corrosive disputes caused by conflicting interests or misunderstandings among licensing partners. The choice made ex ante on mechanisms for resolving potential disputes is of prime importance in the execution of licensing exchanges. Although the legal literature has widely emphasized the advantages of arbitration towards litigation, public ordering remains the “default” option in managers’ eyes. By adopting a transaction cost economics logic, our study explores the conditions under which licensing partners may prefer arbitration over public ordering during the contractual-design phase. In accordance with our theoretical arguments, findings show that the occurrence of arbitration provisions increases when the coordination orientation adopted by licensing partners is extensive. In situations where both monitoring and coordination orientations are simultaneously extensive, results reveal a greater propensity to prefer arbitration over public ordering. Our research therefore supports the view that corporate decision-makers tend to favor the conciliatory stance and compromising awards typically associated with arbitration, only when exchanges are expected to be highly coordinative. Their preference for arbitration over litigation is magnified when the coordination orientation develops alongside the monitoring orientation.  相似文献   

Joint ventures and technology adoption: A Chinese industrial policy that backfired     

Sabrina T. Howell 《Research Policy》2018,47(8):1448-1462

To spur technology transfer, emerging market policymakers often require foreign firms to form joint ventures (JVs) with domestic firms. Through knowledge spillovers, JVs may reduce technology acquisition costs for domestic firms. Yet domestic firm rents from JVs could discourage innovation through a cannibalization effect. Which force dominates is an empirical question. I address it with novel data on China's auto sector. In response to fuel economy standards requiring firms to upgrade technology or sacrifice quality, firms with JVs reduced quality and price relative to their counterparts. Consistent with cannibalization, firms with JVs drive the negative effect.  相似文献   

Development of a computational tool for materials design     

Shuang-Lin Chen  Wei-Sheng Cao  Fan Zhang  Chuan Zhang  Jun Zhu  Jie-Yu Zhang 《上海大学学报(英文版)》2013,(2):123-129

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铌掺杂二氧化钛介孔分子筛的合成及其光催化活性研究     

刘义章  何杰 《六安师专学报》2013,(2):59-62

以十六烷基三甲基胺为模板剂,钛酸正四丁酯为钛前驱体,草酸铌为铌的前驱体,用溶胶一凝胶手段,将铌元素引入到介孔二氧化钛体系中,制备出了介孔NbzO5Ti02复合氧化物。采用XRD、IR等表征手段对其进行表征,并以苯酚为目标降解物进行了光催化反应活性测试。结果表明：少量铌能进入TiO2骨架,样品保持介孔结构,当铌量进一步增加时,介孔结构遭到破坏;铌的掺杂并不能使介孔TiO2分子筛的光催化活性提高。  相似文献   

热处理工艺对5083铝合金船用板晶间腐蚀的影响     

汪永红  李成华  鄂孔元  李春红 《重庆师专学报》2013,(5):8-12

采用金相显微镜、SEM、EDS,研究热处理工艺对5083铝合金晶间腐蚀的影响.研究结果为：试样经过180℃退火后,内部形成了等轴晶粒,晶界上析出了β相（Mg2Al3）;稳定化试样在350℃下保温4 h,再经过180℃退火保温150 h,其晶间腐蚀深度最小,在50μm以下,晶间腐蚀等级为3级.  相似文献   

Mysteries in the Night: An Exploratory Study of Student Use and Perceptions of 24/5 Hours     

Steven L. Sowell  Jennifer E. Nutefall 《Public Services Quarterly》2013,9(2):96-114

The Oregon State University Valley Library has been open 24 hours per day, five days per week, during regular academic terms since 2010. The authors collected survey data during 2012 to explore how students used the hours and whether they perceived that the provision of 24/5 hours contributes to their academic success. Nearly 90% of the respondents believed that their use of the overnight hours made a difference in their performance. The demographic, usage, and perception of value data collected provide a useful snapshot of overnight usage in this exploratory study.  相似文献